stdev
===
[![NPM version][npm-image]][npm-url] [![Build Status][travis-image]][travis-url] [![Coverage Status][coveralls-image]][coveralls-url] [![Dependencies][dependencies-image]][dependencies-url]
> Computes the sample standard deviation over an array of values.
## Installation
``` bash
$ npm install compute-stdev
```
For use in the browser, use [browserify](https://github.com/substack/node-browserify).
## Usage
To use the module,
``` javascript
var stdev = require( 'compute-stdev' );
```
## Examples
``` javascript
var data = new Array( 1000 );
for ( var i = 0; i < data.length; i++ ) {
data[ i ] = Math.random()*100;
}
console.log( stdev( data ) );
```
To run the example code from the top-level application directory,
``` bash
$ node ./examples/index.js
```
## Tests
### Unit
Unit tests use the [Mocha](http://visionmedia.github.io/mocha) test framework with [Chai](http://chaijs.com) assertions. To run the tests, execute the following command in the top-level application directory:
``` bash
$ make test
```
All new feature development should have corresponding unit tests to validate correct functionality.
### Test Coverage
This repository uses [Istanbul](https://github.com/gotwarlost/istanbul) as its code coverage tool. To generate a test coverage report, execute the following command in the top-level application directory:
``` bash
$ make test-cov
```
Istanbul creates a `./reports/coverage` directory. To access an HTML version of the report,
``` bash
$ open reports/coverage/lcov-report/index.html
```
## License
[MIT license](http://opensource.org/licenses/MIT).
---
## Copyright
Copyright © 2014. Athan Reines.
[npm-image]: http://img.shields.io/npm/v/compute-stdev.svg
[npm-url]: https://npmjs.org/package/compute-stdev
[travis-image]: http://img.shields.io/travis/compute-io/stdev/master.svg
[travis-url]: https://travis-ci.org/compute-io/stdev
[coveralls-image]: https://img.shields.io/coveralls/compute-io/stdev/master.svg
[coveralls-url]: https://coveralls.io/r/compute-io/stdev?branch=master
[dependencies-image]: http://img.shields.io/david/compute-io/stdev.svg
[dependencies-url]: https://david-dm.org/compute-io/stdev
[dev-dependencies-image]: http://img.shields.io/david/dev/compute-io/stdev.svg
[dev-dependencies-url]: https://david-dm.org/dev/compute-io/stdev
[github-issues-image]: http://img.shields.io/github/issues/compute-io/stdev.svg
[github-issues-url]: https://github.com/compute-io/stdev/issues
